Persistent viral infections induce cytotoxic damage, interfere with normal signalling pathways and cellular trafficking in the BM. Viral DNA is often found in the human BM (e.g., herpesviruses, hepatitis B virus, Merkel cell polyomavirus and human papillomavirus). In mice chronic infection with lymphocytic choriomeningitis virus causes long‐lasting destruction of the CAR cell network due to accumulation of activated CD8+ T‐cells in the BM via interferon‐dependent mechanisms decreasing HSC functionality. This evidence concerns the gene CD8A and viral infectious disease.